1. Field of the Invention
The present invention relates to bolts for large chamber rifles that need a mechanical advantage to break a cartridge casing free from a rifle chamber after cartridge firing, facilitating that casing being pulled out of the chamber by operation of the bolt.
2. Prior Art
Heretofore, even for large chamber rifles where some difficulty can be expected to break a cartridge casing free of the rifle chamber, only a solid handle connected to the rifle bolt to be manually operated by a shooter or operator has been provided. With the shooter or operators strength alone being utilized to pull a spent cartridge casing out from a rifle chamber after cartridge firing. In which firing sequence, the casing will expand into tight fitting engagement in and will often "stick" in the rifle chamber, requiring that a strong pulling force be applied thereto to pull it free from that chamber. A recent development in large chamber rifle cartridges of the present invention as embodied in a current U.S. Patent Application of the present invention for a "Cartridge and Method of Manufacturing a Cartridge for a Firearm," filed Jul. 16, 1996, sets out a cartridge with a casing that has a significantly larger circumference than do earlier conventional cartridges. For a rifle utilizing such cartridge, where a rifle bolt is fitted into the cartridge primer end rather than is fitted around it, it has been found that it is difficult for an operator or shooter to apply a sufficient pulling force through a solid handle of a rifle bolt to break a spent cartridge casing out from the chamber to eject it. To solve this problem, the present invention provides a bolt arm that is pivotally connected to extend outwardly from the bolt surface. In operation, the operator or shooter lifts the bolt handle along a receiver vertical slot from a locked attitude into alignment with a horizontal receiver slot, whereat, by pulling a handle end rearwardly, a handle forward shoulder is pivoted against the side of the receiver at the forward end of the horizontal slot. The handle pivot mounting provides a mechanical advantage to increase the pulling force as the operator applies thereto, breaking the spent cartridge casing from its sealing engagement in the rifle chamber. Thereafter, the casing can be easily pulled from the rifle chamber by the operator holding the handle end and pulling the bolt rearwardly along the horizontal slot to where the spent casing is ejected from the receiver.